The reason it’s not done “this way” or “that way” even when those are objectively better ways to achieve the stated goal, but rather in an unexplainable way broader way is because the goal is broader that that and age verification is just the tip of the spear. The rest of it is laying the groundwork for a framework to control the freedom on the internet by linking identity to speech and action.
Look at what solution is implemented to decide what problem is it supposed to fix, otherwise you’re just looking at the smoke and mirrors.
Not that every state and country is on board with this, but it’s getting a lot harder to maintain the pressure to keep these initiatives down. Every time they get pushed one step forward it’s that much harder to regain that ground.
There are a lot of different people in different countries pushing for age verification and I imagine they wouldn't all have the same motives.